APANTELES MELANOSCELUS GIPSY-MOTH PARASITE. 



17 



During the spring of 1912 the adults which issued from these cocoons 

 were liberated near the laboratory. 



Early in 1912 Mr. Fiske again went to Italy, this time with several 

 assistants. As one of the results of this trip, 22,000 cocoons of the 

 second generation of A. melanoscelus were received during the 

 sumimer of 1912. These cocoons were collected in the forest of San 

 Pietro, near Caltagirone, Sicily, during the week beginning June 15. 

 They were shipped to Naples in cold storage on June 22 and held 

 there in cold storage until all had been isolated in gelatin capsules. 

 Early in July they were sent to America in cold storage and hiber- 

 nated at the laboratory. The adults which issued in the spring of 

 1913 were liberated at Melrose. 



Table 1 shows the number of individuals of A. melanoscelus that 

 have been liberated in New England. The colonizations of 1911, 

 1912, and 1913 were adults which issued from cocoons received from 

 Sicily ; the rest of the colonization material was obtained by rearing 

 and breeding New England material. 



Table 1. — Numher of A. melanoscelus liberated in New England, 1911-1920. 



Year. 



Number 

 of adults 

 liberated, 

 Sicilian 

 material. 



Cocoons 

 colonized. 



New 

 England 

 material. 



Number 

 of colonies 

 placed in 

 Massa- 

 chusetts. 



Number 

 of colonies 

 placed in 



New 

 Hamp- 

 shire. 



Number 



of colonies 



placed in 



Rhode 



Island. 



Total 

 number 



of 

 colonies. 



1911 . 



23,000 

 203 

 273 





1 

 1 



1 

 2 







1 



1912 









1 



1913 









1 



1915 



1,500 

 5,541 

 3,500 

 8,100 

 930 

 10, 100 



1 





3 



1916 





11 







11 



1917 - . . 



'■ 



7 

 9 

 2 

 11 







7 



1918 





7 





16 



1919 







2 



1920 





9 



1 



21 









Total 



23, 476 



29, 671 



45 



17 



1 



63 







As will be seen from a study of the figures in Table 1, very few 

 adults were liberated in 1912 from the 17,000 cocoons received in 

 1911, and in 1913 from the 22,000 cocoons received in 1912. The 

 poor issuance from these imported cocoons was due to several factors. 

 Fifty to seventy-five per cent were killed by secondaries and a few 

 were injured while being collected. These cocoons were kept in 

 gelatin capsules from the middle of the summer until the adults 

 issued the following spring. Subsequent experiments have shown 

 that the mortality of hibernating larvse of Apanteles melanoscelus 

 was not so high when the cocoons were isolated in Small glass vials 

 plugged with cotton batting as when they were kept in gelatin cap- 

 sules. An examination of dead maggots of A. melanoscelus, which 

 had been isolated in gelatin capsules, showed that the maggots were 



